Em dash: the regular dash

The em dash (—), or long dash, is probably the most versatile punctuation mark because it can be used in place of a comma, parenthesis or colon. This dash is the popular dash, the longer of the two dashes (en dash and em dash).

An em dash is twice as long as the en dash and three times longer than the hyphen. It is said to have derived its name from the length of hyphen. It is said to have derived its name from the length of letter ‘m’.